Paving material and process of manufacturing the same



Aug; 11, 1931. R. 1.. WHITE PAVING MATERIAL AND PROCESS OF MA NUFACTURING THE SAME Filed Nov. 5. 1929 Patented Aug. 11, 1931 RYALL L. wnrmnor SAN ANTONIO, TEXAS PAVING MATERIAL AND rnocnss OFyMANUFACT-URING THE SAME Application filed November 5, 1929. Serial No. 404,970.

' This invention relates to improvements in paving 1naterials, andto a novel method or process for manufacturing such materials.

'Asphaltic or bituminous paving materials heretofore used havegenerally been mixed and applied directly at the roadway to be surfaced, or have been premixed at the plant and'maintained in heated condition until the time of'laying; Some effort has also been made to mix such materials at the mines or the like, and to incorporate in the vmaterials, substances to keep the adhesive inactive until the material was actually spread on the roadwayto be surfaced; This latter effort has disadvantages, due to the expense involved. I

The primary object. ofthe present invention is to eliminate the disadvantages inherent in the prior paving materials, and

present inthe methodsemployed'; and inaccordance with my invention, the materials I are mixed at the mine, and are so balanced that the mixture may beshipped to distant points and remain inertv until such timeas it is spread. VVhen the mixture is spread,

the water which maintains the same inert, while in bulk, rapidly evaporates, and the mixture hardens' and properly sets, thus securing a more uniform'and less expensive job than was formerly possible by the mixing of the material in situ' by workmen of limited experience. I v

Another object of this invention is V to furnish a method in which a crude oil having a comparatively high Baume gravity and lowasphaltic content, is first added ,to

v pulverized rock asphalt at the quarry for I the purpose of securing a preliminary fluxing and softening effect on the rock asphalt. Thena cru'de oil havingfa comparatively low Baum gravity and tent is added to the mixture,

, for'the purpose of furnishing" additional bitumen to give the necessary binding or'adhesion, and

finally a properamount of water is added to render the adhesive qualities of the asphalt temporarily inactive, so that the mixture, whileshipped or stored in bulk,

will have the desired plasticity. When, however, such mixture is spread, the aqueous high asphaltic conmoisture therein will evaporate, and permit the binding substances to again become active, whereby the mixture rapidly hardens andproperlyrsets, From the above it will be understood that my improvedpavin-g material in bulk con-' dition, will consist of pulverized rock asphalt or the like, a fluxing oil having a comparatively high Baum gravity, and low asphaltic content; a fluxing oil having a comparatively low Bau-m gravity and a high, asphaltic content; and suflicient water torender the adhesive qualities of the asphalt temporarily inactive. vWhen such material is spread, and after hardening and setting, it will be ofabout the 'samecomposi'tion, minus all 'or substantially all-of its water content. v

Various apparatus may be employed in the manufacture of "my paving .material, and

one form o'fsuit'a ble apparatus is illustrated in the accompanying drawing, which shows a diagrammatic view of such an apparatus.

Referring to the method of'manufacture in detail, in connection with this drawing, 7 the rock-asphalt or the like, when received *frOmthe quarry, is discharged from, the dump car vA into a 42 inch crusher B, which maybe of theSuperior McCully gyratory type. The discharge opening at the bottom ofthisc'rusher isthree andone-half inches in area, and theroc'k asphalt, after passing. I

throughthe crusher, is dischargedinto a pan conveyor C, and elevated tothe top of a steel bin D, where it is discharged on .to an apron conveyor E and distributed therfull lengthof the bin.

As the pulverized rock asphalt or the like,

used injmypaving material, varies from three-eighths to one-half inch in size, the

material is conveyed from the bottom of the I bin by'an apron conveyor F, and discharged into a suitable pulverizer G, which reduces the same to proper size. After the material is pulverized, it passes into a bucket conveyor H which elevates the same approximately sixtyfe'et. From this elevation, it is either discharged into "a railroad car I, in case just regular run is required, or if it is pulverized rock asphalt m to be employed in preparing my improved paving material, it is discharged into a chute J which leads to the bottom of another small bucket elevator K, used in connection with the mixing plant. After passing into the bucket elevator of the mixing plant, it is elevated to a height of approximately thirty feet, andis discharged into a hopper L, Where it is measured ofi 1n batches of say 1500 pounds per batch. From this hopper, the pulverized rock asphalt or the like passes into a suitable mill M, of the pug or drum type. \Nhile the mill is operating on the batch, approximately three gallons of the first flux oil is added, and,

thoroughly mixed with the pulverized material. This flux oil is preferably a crude oil having a comparatively high Baume gravity and low asphaltic content for the purpose of securing a preliminary fluxing and softening effect. Such oil may have the characteristics of the Luling product, which are as follows:

Gravity 27 Flash 110 F. Sulphur 68/100 of 1% B. S. & W 1/2 of 1% Cold test 10% F. Viscosity 1.81 70% 7 Per cent Naptha -1 Kerosene 5.0 Gas oil 27. 7 Crude lube 35.7 Asphalt 19.7 Loss by distillation 1. 6

This first flux oil may be fed to the mixing mill from a measuring tank N, through a valved pipe line 0.

After this flux oil has been thoroughly mixed with the pulverized material, approximately three gallons of a second flux oil from a measuring tank P may be fed into the material in the mill M, through a valved pipe line Q. This second flux oil preferably should have a comparatively low Baum gravity and a high asphaltic content for the purpose of furnishing. additional bitumen to give the necessary binding or ad hesion to the finished paving material. I have found Hondo crude admirably adapted for this :purpose. It tests as follows:

Gravity A. P. I 16 Flash point 1 187 F. Asphalt content 63% Total bitumen (soluble in carbon disulphide) 99.5% Organic matter insoluble 0.00 Water 0.1% Sediment 0.1% B. S. WV.

Instead of using Hondo, I may use any flux o1l havmg similar character1st1cs. For

' example, I have also used in the mixture in substitution for the Hondo crude, an oil testing as follows:

SpLgravity 60 F .9541

After the flux oils have been thoroughly mixed with the pulverized material, approximately six gallons of water is added to the batch and admixed into the mixture. The mixture remains in the mill M for a periodof approximately two minutes, and is then discharged into a railroad car It or the like, for shipment to the point of utilization.

As before stated, the water will render the adhesive qualities of the asphalt inactive until such time as the water evaporates. Obviously, if the i nished material is in bulk, there will be less tendency for the aqueous moisture to depart than if the material is spread out in a relatively thin layer.

While I have disclosed my .invention in such manner that the same may be readily understood by those skilled in the art, I am aware that changes may be made in the specific materials employed, and in the details of the method, without departing from the spirit of the invention, as expressed in the appended claims.

WhatI claim and desire to secure by Letters Patent is 1. Paving material comprising pulverized rock asphalt, sufficient flux oil having comparatively high Baum gravity and low asphaltic content, but containing appreciable quantities of asphalt, to secure a prelimi-.

nary fiuxing and softening effect on the rock asphalt, asufticient quantity of a second as phaltic flux oil sufliciently fluid at ordinary temperatures so that it can be thoroughly mixed cold with the rock asphalt, said second flux oil having a comparatively low Baum gravity and high asphaltic content for the purpose of furnishing additional bitumen to g1ve the necessary binding qualities to the material, and a sufficient quan tity of Water to render the adhesive qualities of the asphalt temporarily inactive.

2. The paving material as in claim 1, wherein the proportions of ingredients are approximately as follows, 1500 pounds of rock asphalt, ,3gallons of flux oil of comparatively high Baum gravity and low as phaltlc content, 3 gallons of asphaltic Oil of comparatively low Baum gravity and high asphaltic content, and 6 gallons of water.

BYALL L. WHITE. 

